The subject matter disclosed herein relates to the art of turbomachines and, more particularly, to a transition piece seal assembly for a turbomachine.
Many turbomachines include a compressor portion linked to a turbine portion through a common compressor/turbine shaft or rotor and a combustor assembly. The compressor portion guides a compressed airflow through a number of sequential stages toward the combustor assembly. In the combustor assembly, the compressed airflow mixes with a fuel to form a combustible mixture. The combustible mixture is combusted in the combustor assembly to form hot gases. The hot gases are guided to the turbine portion through a transition piece. The hot gases expand through the turbine portion along a hot gas path creating work that is output, for example, to power a generator, a pump, provide power to a vehicle such as an aircraft or the like. In addition to providing compressed air for combustion, a portion of the compressed airflow is passed through the turbine portion for cooling purposes.
A seal is provided between the transition piece and a first stage of the turbine portion. The seal reduces leakage of lower temperature gases from the compressor flowing into high temperature gasses passing to the turbine portion. As such the seal is exposed to hot gases flowing through the transition piece. The seal is also configured to accommodate relative expansions of the transition piece and the turbine portion. More specifically, the transition piece and the turbine portion are often formed from dissimilar materials. Accordingly, the transition piece and the turbine portion will experience different rates of expansion when exposed to the hot gases. The seal is configured to accommodate these different rates of expansion and still limit any escape of the hot gases.